Captions, Transcripts, and Audio Description

Without providing appropriate alternate formats such as captions, transcripts, and audio descriptions, multimedia content is inaccessible to people who are unable to hear audio and to blind people or those with low vision who can’t see material presented visually. In addition, alternate media formats can benefit all people, including those with learning disabilities, non-native language speakers, people in noisy environments, or when the material contains proper names or technical references.


Many platforms offer captions generated by automatic speech recognition (ASR). Although the technology is constantly improving, ASR captions usually need human correction to reach acceptable accuracy levels. Captions and transcripts can be corrected by faculty, staff, student workers, or third-party vendors. This can be a time-consuming process, so a vendor may be the best choice if you need a quick turnaround.


Captions are a text version of the speech and non-speech audio information needed to understand multimedia content. They are displayed within the media player and synchronized with the audio.

Captions are required for all live and prerecorded multimedia content.

Closed vs. open captions

Closed captions are generally preferable to open captions. Closed captions can be turned on and off, provide the user more control over caption display, and are accessible to assistive technology. Open captions are burned into the video during editing, can’t be disabled, and are not accessible to screen readers. If open captions are used, they should not obscure or obstruct relevant information in the video.


A transcript is the text version of media content and benefits many types of people, including deaf-blind users who may consume the content via a refreshable braille keyboard, screen-reader users, and people who have difficulty processing auditory information.

A transcript is required for prerecorded audio-only content. For prerecorded video-only or multimedia content, a transcript or audio track presenting equivalent information is recommended. Make it easy for users to find the transcript by either placing it or a link to it directly under the video on your webpage.

Audio description

Audio Description (AD) is a secondary audio track of narration describing important visual details that cannot be understood from the main soundtrack alone. AD benefits individuals who are blind, have low vision, or are visually impaired, and those who are unable or choose not to view the video.

Audio description is required for prerecorded multimedia content and prerecorded video-only content. Note: This guideline can be met by describing all visual content critical to comprehension within the primary audio track itself.

Learn more about the Audio Description Project, an initiative of the American Council of the Blind.

Multimedia accessibility decision matrix

Use the table below as a guide for when a particular alternative media format is required in order to maintain WCAG 2.1 AA compliance.

Captions Transcript Audio Description
Pre-recorded Multimedia Required Recommended Required
Pre-recorded Video-only N/A Recommended Required
Pre-recorded Audio-only N/A Required N/A
Live Multimedia Required N/A Optional
Live Video-only N/A Optional Optional
Live Audio-only Optional Optional N/A

Prioritizing alternative media formats

Course content

Accommodations for students registered with Student Disability Services (SDS) are required. SDS will coordinate with relevant parties when an academic accommodation requires alternative media formats.

Place a high priority on offering human-generated or corrected captions for content that is part of ongoing curriculum, particularly if it will continue to be used beyond the current quarter or made public.

New public-facing content

Captions and transcripts of new media content on websites or social media must be human-generated or corrected before they are posted.

Older public-facing content

For existing content on a website or social media platform:

  • User requests for captions or transcripts must be fulfilled in a timely manner.
  • Update captions and transcripts of most visited items before those least visited.
  • Assess whether media should be removed if no longer necessary or relevant.


Following is a partial list of vendors previously used by the University for captioning and other services. Please reach out to vendors directly for more information. You may want to consult with Student Disability Services if you have questions about contracting service providers.

Real-time Services

Vendor Video captioning (CART) ASL interpreting, on site ASL interpreting, video remote
ACS Yes Yes Yes
American Language Services Yes Yes Yes
Chicago Hearing Society Yes Yes Yes
3Play Media Yes No No
CaptionSync Yes No No
Dillon Reporting Service Yes No No

Post-production Services

Vendor Translation Video captioning Audio transcription Audio description
3Play Media Yes Yes Yes Yes
CaptionSync Yes Yes Yes Yes
ACS Yes Yes Yes No
American Language Services Yes No Yes No

Additional Resources